Intradermal Syringe and Needle Assembly

ABSTRACT

A device and method for making an injection with a short needle, which includes a needle cannula and a limiter surrounding the needle cannula and includes a skin engaging surface on the limiter. The limiter is moveable from a first position in which an elongate portion of the needle cannula is exposed for access to a medication vial, to a locked second position in which the limiter is not movable from the second position to the first position. In the second position, the needle tip extends beyond the skin engaging surface a distance which is ordinarily unable to access the vial.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 12/361,788 filed on Jan. 29, 2009, which is a continuation ofU.S. patent application Ser. No. 11/774,640 filed on Jul. 9, 2007, nowU.S. Pat. No. 7,497,841 which is a continuation of U.S. patentapplication Ser. No. 11/463,677 filed on Aug. 10, 2006, now U.S. Pat.No. 7,250,036, which is a continuation of U.S. patent application Ser.No. 10/798,594 filed on Mar. 11, 2004, now U.S. Pat. No. 7,108,679.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a delivery device for injecting drugs,vaccines, and the like into the intradermal region of the skin.

2. Description of Related Art

There are several injection techniques and devices known in the art.Based on the drug substance being injected, one technique and device mayprovide for a more efficacious delivery and uptake of the particulardrug substance. One technique and device delivers a drug substanceintramuscularly using a hypodermic needle that penetrates through apatient's skin and into muscle tissue.

Another technique and device delivers a drug substance into thesubcutaneous region of the skin. It is possible that the same device maybe used to delivery an intramuscular and a subcutaneous injection, withthe health care provider controlling the depth of the injection.

Techniques and devices are also known for administering an injectioninto the intradermal (intradermal) region of the skin. One technique,commonly referred to as the Mantoux technique, uses a “standard”syringe, i.e., a syringe typically used to administer intramuscular orsubcutaneous injections. The health care provider administering theinjection follows a specific procedure that requires a somewhat preciseorientation of the syringe with regard to the patient's skin as theinjection is administered. The health care provider must also attempt toprecisely control the penetration depth of the needle into the patient'sskin to ensure that it does not penetrate beyond the intradermal region.Such a technique is complicated, difficult to administer, and often mayonly be administered by an experienced health care professional.

Devices have been proposed for providing intradermal injections whichinclude shortened fine gauge needles compared to conventional needlesizes. The smaller needles are not intended to penetrate beyond thedermis layer of the skin. Such devices are shown in U.S. Pat. No.5,527,288 to Gross et al., U.S. Pat. No. 4,886,499 to Cirelli et al.,and U.S. Pat. No. 5,328,483 to Jacoby. The proposed devices, however arenot without shortcomings and drawbacks.

For example, the devices shown in U.S. Pat. Nos. 5,527,288 and 4,886,499are highly specialized injectors. The designs for these injectorsinclude relatively complex arrangements of components that cannot beeconomically manufactured on a mass production scale. Therefore, suchdevices have limited applicability and use.

For many drug substances, it may be desirable to fill the deliverydevice at the point of, and immediately prior to use. In this situation,the delivery device is normally filled from a multi-dose vial. Amulti-dose vial may be more economical and it enables the user to fillthe delivery device with the specific dose required. The multi-dose vialmay be pre-filled with a liquid substance or with a dry substance. Forexample, it is now conventional to reduce certain drugs to a dry orpowdered form to increase the shelf life of drugs and reduce inventoryspace. Multi-dose vials are typically sealed with an elastomeric stopperor septum. A needle on the delivery device may be used to pierce thestopper or septum and draw the drug substance from the vial into thedelivery device, typically a syringe. The drug substance may then beadministered using the delivery device, which is discarded after use,and the unit-dose vial may be stored for further use.

As advances in understanding the delivery of drug proceeds, the use ofintradermal delivery systems is expected to increase. Use of a“standard” length needle to deliver a drug substance intradermally hasits shortcomings, come of which are identified above. It is not possibleto use a delivery device having a needle length suited for intradermalinjection to aspirate a syringe with drug substance from a multi-usevial. Thus, there are shortcomings in the prior art that preventadministering an intradermal injection using a “standard” length needleand a multi-use vial. It would be advantageous to have a drug deliverydevice capable of accessing substances stored in multi-dose vials anddelivering such substances into the intradermal region of the skinwithout encountering the shortcomings described above.

FIG. 1 shows an intradermal injection device 101 comprising a syringe114 having a syringe body 116 that defines a reservoir 118 within whicha drug substance may be held, a plunger 120 disposed in the syringe body116 and having a flange 122 at a distal end thereof and a stopper 124 atthe opposed proximal end thereof, and a needle assembly 102 secured to adistal end of the syringe body 116. An exemplary needle assembly 102 ofthe type depicted in FIG. 1 is disclosed in U.S. Pat. No. 6,494,865 toAlchas, the entire contents of which is incorporated by referenceherein. The needle assembly 102 is specifically designed for makingintradermal injections. The needle assembly 102 may carry a needlecannula 104 having a needle tip 106 at a distal end thereof.Alternatively, the needle cannula 104 may be secured directly to thesyringe body 116. The needle assembly 102 also includes a penetrationlimiter 108 having a hub portion 109 that may be secured to the syringebody 116, and a limiter portion 111 that defines a generally flat skinengaging surface 110 at a distal end of the limiter 108. The limiter108, which generally surrounds the proximal end of the needle 104,permits a certain predetermined length of the needle cannula 104,including the needle tip 106, to protrude beyond the skin engagingsurface 110 so that the distance between the needle tip 106 and skinengaging surface 110 limits penetration of the needle tip 106 into theintradermal space of the patient's skin. Preferably, the needle tip 106of the needle cannula 104 extends beyond the skin engaging surface 110 adistance ranging from approximately 0.5 mm to 3 mm. The needle cannula104 and skin engaging surface 110 are also arranged with respect to eachother in a generally perpendicular relationship that serves to ensure agenerally perpendicular relationship between the needle cannula 104 andthe patient's skin; such an angular relationship being preferred whenmaking intradermal injections. The skin engaging surface 110 engages thesurface of the skin of a patient and limits the penetration depth of theneedle tip 106 into the patient's skin. The needle assembly 102 issecured to the syringe 114 via the hub portion 109, which may be fixedlysecured to the syringe body 116, or the hub portion 109 may be securedby a Luer fit or equivalent attachment method.

Referring now to FIG. 2, a conventional syringe 114 being filled from amulti-use vial 126 is shown. The vial 126 includes an open end, a rimsurrounding the open end and a reduced diameter neck portion adjacentthe rim. The vial 124 is typically sealed with an elastomeric septum 128which includes a portion inserted into the neck of the vial 126 and aplanar rim portion which overlies the vial rim. The septum 128 isnormally secured to the vial rim with an aluminum collar 130. In FIG. 2,a conventional syringe 114 is being used to access a drug substancecontained within the vial 126. The needle 104 in this case issufficiently long to penetrate the septum 128 to access the drugsubstance contained in the vial 126.

As may be appreciated from FIGS. 1 and 2, it is not possible, using adevice having a stationary limiter, to fill a reservoir from aconventional vial. The distance d is too short to adequately penetratethe depth of the septum and access the substance contained in the vial.The present invention allows for access to a substance contained in aconventional vial by an intradermal needle device or assembly. As aresult, there is no need to pre-fill an intradermal device of thepresent invention prior to use. Thus, standard methods for preservingthe therapeutic and/or diagnostic substances, such as maintaining themin liquid or powder form in conventional vials for future use, may beused with the intradermal devices of the present invention. Furthermore,using the intradermal devices of the present invention, it is possibleto use conventional, inexpensive delivery devices such as plasticsyringes, in conjunction with the intradermal devices, which are oftennot appropriate for use as pre-filled devices.

In light of the above, there is a present need for a drug deliverydevice intradermal that enables a user to fill the intradermal devicewith a drug substance at the time of use by aspiration from a multi-dosevial, and to administer an injection into the intradermal region of theskin easily and repeatedly and without relying on the experience of thehealth care professional administering the injection.

SUMMARY OF THE INVENTION

The present invention provides a drug delivery device that overcomes theabove-described shortcomings of the prior art. In an embodiment of thepresent invention, intradermal the drug delivery device, also referredto herein as an intradermal injection device, comprises a syringe havinga needle cannula and a limiter that is movable with respect to theforward tip of the needle cannula between a first position in which alength of the needle cannula is exposed that is sufficient to enableaspiration of a drug substance from a multi-dose vial into the syringe,and a second position in which a length of the needle cannula is exposedthat is preferably approximately equal to or less than 3 mm, whenmeasured from the forward tip of the needle cannula to a top surface ofthe limiter.

As used herein, the term “proximal” and derivatives thereof, shall meanthe end of an item or direction away from a patient during use of thesubject invention. The term “distal”, and derivatives thereof, shallmean the end of an item or direction towards a patient during use of thesubject invention. As used herein, the term “drug substance” andderivatives thereof, shall mean any substance that is intended forinjection into a patient, including, by way of non-limiting example,drugs, vaccines, therapeutics, and the like. It will be obvious to aperson of skill in the art, and from the disclosure provided herein,that the subject invention is not limited or otherwise defined by thetype or class of substance administered using the inventive injectiondevice.

An intradermal injection device constructed in accordance withembodiments of the present invention includes a syringe defining areservoir in which a drug substance may be held, a needle cannula havinga proximal end provided at a distal end of the syringe and in fluidcommunication with the reservoir and a distal needle tip. The inventiveinjection device also includes a movable limiter having a skin engagingsurface with an aperture defined therethrough and through which theneedle cannula may pass. The limiter is selectively moveable from afirst refracted position in which an elongate portion (d₁) of the needlecannula is exposed and extends through the aperture and beyond the skinengaging surface, and a locked second extended position in which thelimiter may not be moved from the second position back to the firstposition and in which the portion of the needle cannula exposed andextending through the aperture and beyond the skin engaging is limitedto about 3 mm or less.

The present invention is also directed to a needle assembly for use inconnection with a syringe for administering an intradermal injection.The inventive needle assembly may be coupled to a syringe and include aneedle cannula having a proximal end provided at a distal end of thesyringe and in fluid communication with the reservoir and a distalneedle tip. The inventive needle assembly also includes a movablelimiter having a skin engaging surface with an aperture definedtherethrough and through which the needle cannula may pass. The limiteris selectively moveable from a first retracted position in which anelongate portion (d₁) of the needle cannula is exposed and extendsthrough the aperture and beyond the skin engaging surface, and alockable second extended position in which the limiter may not be movedback to the first position and in which the portion of the needlecannula exposed and extending through the aperture and beyond the skinengaging is limited to about 3 mm or less. The needle assembly may becoupled to the syringe using a luer-type connector, via a friction fit,using adhesive, or other now know or hereafter developed techniques forsecuring a needle cannula to a syringe.

Additionally, a method of intradermally injecting a mammal with asubstance is provided including the steps of pressing a needle assemblyof the invention in an orientation substantially perpendicular to thepatient's skin such that the skin engaging surface of the limiterencounters the skin and prevents penetration of the needle cannuladeeper than about 3 mm; maintaining the skin engaging surface on theskin and the orientation of the needle assembly; and injecting thesubstance under conditions and for a time sufficient to deliver thesubstance into the dermis layer of the skin.

The various features and advantages of this invention will becomeapparent to those skilled in the art from the following detaileddescription of the currently preferred embodiments. While this inventionis satisfied by embodiments in many different forms, there is shown inthe drawings and will herein be described in detail preferredembodiments of the invention with the understanding that the presentdisclosure is to be considered as exemplary of the principles of theinvention and is not intended to limit the invention to the embodimentsillustrated. The scope of the invention will be measured by the appendedclaims and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a partial cross-sectional view of an intradermal injectiondevice having a non-movable penetration limiter; intradermal

FIG. 2 shows a perspective view of a conventional syringe being filledfrom a multi-dose vial;

FIG. 3 shows an intradermal injection device having a needle assemblewith a movable penetration limiter in the refracted position andconstructed in accordance with an embodiment of the present invention;

FIG. 4A shows a partial cross-sectional view of a needle assembly havinga movable penetration limiter located in a retracted position andconstructed in accordance with an embodiment of the present invention;and

FIG. 4B shows the needle assembly of FIG. 4A with the movablepenetration limiter in an extended position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring next to the drawings in detail, in which like characters referto like parts throughout the several views, FIGS. 3, 4A and 4B depict anintradermal injection device 2 and needle assembly 4, each constructedin accordance with embodiments of the present invention. The inventiveinjection device 1 includes a syringe 114 having a cylindrical body 116that defines a reservoir 118 within which a drug substance may becontained and from which such substance may be expelled. A plunger 20having a stopper 24 secured thereto is selectively movable within thereservoir 118, where movement in the proximal to distal direction willcause the drug substance to be expelled from the reservoir 118 throughthe needle cannula 4.

The inventive injection device 1 also includes a needle assembly 2 atthe distal end of the body 116. The needle assembly 2 includes a needlecannula 4 supported by an inner support member 36 which is located atthe distal end of the body 116. In the embodiment depicted in FIG. 3,inner support member 36 of the needle assembly 2 is secured to a hub 12defined at that distal end of the body 116 in a manner known to thoseskilled in the art. For example, inner support member 36 may be securedusing a friction fit, snap fit, suitable adhesive, luer connection, orother now known or hereafter developed means of securing a needleassembly to a syringe body. Alternatively, the needle cannula 4 may besecured directly to the body 116 via the hub 12 or other suitablestructure that provides sufficient stability of connection between theneedle cannula 4 and body 116 and that permits fluid communicationbetween the reservoir 118 and needle cannula 4.

The needle assembly 2 further includes a limiter 32 comprised of anouter sheath 34 and the inner support member 36. In the embodimentdepicted in FIG. 3, the inner support member 36 performs the function ofa conventional hub. It is also possible to separately form a hub and aninner support member. However, for ease in construction, it is preferredthat the hub and inner support member be formed unitarily. The outersheath 34 has a generally flat skin engaging surface 10 defined at itsdistal end. The skin engaging surface 10 is preferably generally planarand continuous and provides for stable placement of the inventiveinjection device 1 against a patient's skin. The skin engaging surface10 may, however, have alternate configurations. An aperture 38 isdefined through the skin engaging surface 10 that is sized and shaped topermit the needle cannula 4 to pass freely therethrough when the outersheath 34 is moved from the first position to the second position, asdiscussed in more detail below and elsewhere herein.

The outer sheath 34 is a generally tubular member that is selectivelymovable between a first refracted position, depicted in FIG. 4A, inwhich the a first predetermined length of the needle cannula 4 isexposed, and a locked second extended position, depicted in FIG. 4B, inwhich the limiter may not be moved back to the first position and inwhich a second predetermined length of the needle cannula 4 is exposed;the second predetermined length being shorter than the firstpredetermined length. When the sheath 34 is in the retracted position,as shown in FIG. 4A, the needle cannula 4 extends through the aperture38 and the needle tip 6 is located a predetermined distance d₁ beyondthe skin engaging surface 10; the predetermined distance preferablybeing in excess of about 5 mm. Preferably, d₁ is in the range of about 8mm to about 15 mm, more preferably, d₁ is in the range of about 10 mm toabout 13 mm. The length d₁ is sufficient to permit a user to insert theneedle tip 6 into a conventional multi-use vial to withdraw a drugsubstance stored therein.

The outer sheath 34 is preferably in the first position depicted in FIG.4A when it is desired to aspirate the syringe 14 with a drug substancefrom a multi-use vial. Once the desired dose is drawn into the reservoir18 (by causing the plunger 120 and stopper 124 to move in a distal toproximal direction), the outer sheath 34 may be moved from the firstposition to the locked second position, depicted in FIG. 4B.

The sheath 34 is selectively movable on and along the support member 36from a refracted position as illustrated in FIG. 4A, in which anelongate portion d₁ of the needle cannula 4, including the needle tip 6,is exposed through the aperture 38 and extends beyond the skin engagingsurface 10, to a locked extended position as illustrated in FIG. 4B, inwhich a shorter portion d₂ of the needle cannula 4, including the needletip 6, is exposed through the aperture 38 and extends beyond the skinengaging surface 10.

The inner support member 36 resides at least partially within the sheath34 and is shown carrying the needle cannula 4 and being attached at adistal end of the syringe body 116. However, it is to be understood thatother configurations are possible. For example, it is possible for theneedle cannula 4 to be carried directly by the syringe body 116, eitherbeing secured directly to the syringe body 116 or being removablysecurable thereto. Additionally, the support member 36 may be formedunitarily with the syringe body 116 such that elements defined on thesupport member 36 as described below, will be formed on the syringe body116. Each of these configurations is envisioned as within the scope ofthe invention, as are other configurations which will be apparent tothose having ordinary skill in the art from the disclosure providedherein.

As discussed in further detail below, an inner surface 40 of the outersheath 34 and an outer surface 42 of the inner support member 36 havecooperating parts which releasably secure the outer sheath 34 in therefracted position, and which lockingly secure the outer sheath 34 inthe extended position.

Referring again to FIG. 4A, the outer sheath 34 may be releasably heldin the retracted position by an inwardly directed projection 44 providedtoward a proximal end of the sheath 34 and a corresponding recess 46defined in the outer surface 42 of the support member 36 and bound by aretaining projection 48 and a proximal stop 50. The recess 46 is adaptedto accept the projection 44 when the sheath 34 is in the refractedposition. Movement of the sheath 34 in the proximal direction from theretracted position depicted in FIG. 4A is obstructed by interferencebetween the projection 44 and proximal stop 50. Movement of the sheath34 in the distal direction from the refracted position depicted in FIG.4A is possible by applying sufficient force so that the projection 44overcomes the retaining projection 48.

Upon application of a manual distal force to the sheath 34, the inwardlydirected projection 44 moves out of the retaining recess 46 and movesdistally beyond the retaining projection 48. The inwardly directedprojection 44 then moves relatively along a cylindrical guide portion 52of the support member 36.

Referring next to FIG. 4B, sheath 34 may be lockingly held in theextended position by complementary features defined on the sheath 34 andsupport member 36. A ramp 54, indent 56 and distal stop 58 are providedtoward a distal end of the support member 36. The ramp 54 iswedge-shaped and is wider at its distal end than at its proximal end.The indent 56 is sized and shaped so as to accommodate the inwardlydirected projection 44. The distal stop 58 prevents the inwardlydirecting projection 44 from moving distally beyond the indent 56, i.e.,prevents the sheath 34 from being removed from the support member 36.

Once the sheath 34 is moved along the cylindrical guide portion 52, theinwardly directed projection 44 of the sheath 34 slides up and over theramp 54 into the indent 56. When the sheath 34 is positioned as shown inFIG. 4B, with the inwardly directed projection 44 abutting the ramp 54,the needle tip 6 extends beyond the skin engaging surface 10 a distanceranging from approximately 0.5 to 3 mm. Preferably, the length theneedle tip 6 extends beyond the skin engaging surface is sufficient tolimit penetration of the needle cannula into the dermis, to a depth of 3mm or less. More preferably, the length ranges from about 1 mm to about2 mm.

Once the sheath 34 is in the extended position, the inventiveintradermal device 1 is ready for use in administering an intradermalinjection. Under normal conditions of use, pressure on the skin engagingsurface 10 during an intradermal injection will move the inwardlydirected projection 44 proximally in the indent 56 until a proximal edge60 of the inwardly directed projection 44 abuts a distal edge 62 of theramp 54.

The sheath 34, although preferably rigid, possesses sufficientelasticity to permit sufficient expansion to slide over the retainingprojection 48 and/or the ramp 54 without damage to the sheath 34.Alternatively, or additionally, the support member 36 will possesssufficient flexibility to yield sufficiently to allow a substantiallyrigid sheath 34 to move beyond the retaining projection 48 and/or theramp 54. However, the flexibility of the sheath 34 and/or support member36 will not permit proximal movement of the sheath 34 from the extendedposition to the refracted position when exposed to forces normallyassociated with the use of injection devices.

In a further aspect of the invention, the inwardly directed projection44 and the ramp 54 are configured so that when the sheath 34 is moveddistally from the refracted position into the extended position, theinwardly directed projection 44 will snap past the end of the ramp 54,making an audible sound to provide an audible indication that the sheath34 is in the extended position.

In a preferred embodiment of the present invention, all components ofthe intradermal device 2 will be made from moldable plastic materialssuch as, for example, polymeric plastics such as polypropylene,polycarbonate, and the like (except for the needle cannula 4 which ispreferably made from steel). This construction allows for the syringebody 16 and the inner sheath 34 to be unitarily formed from a singlemoldable plastic. This is especially helpful in ease of assembly as wellas reducing costs of manufacture.

The needle assembly 2 of the present invention may be supplied as anadd-on to conventional drug delivery devices, i.e., glass or plasticsyringes. In that case, the needle assembly 2 may be attached to aconventional drug delivery device, such as a syringe at the point ofuse. Alternatively, the needle assembly 2 may be provided with a syringe14, thus comprising an intradermal device 1 in accordance withembodiments of the present invention. Generally, the intradermal device1 will be provided with a protective packaging to maintain the integrityof the unit and/or sterility thereof. The intradermal device 1 mayfurther be provided with a protective cap to cover the needle tip priorto use thereof.

In use, a health care professional administering the intradermalinjection will unwrap the protective packaging from the needle assembly2 (if provided as a separate component) or injection device 1. Ifnecessary, the injection device 1 can be filled with the drug substanceat this time, using methods that are conventional and known in the art.The health care professional will then manually slide the sheath 34 ofthe limiter 32 from the refracted position (see, e.g., FIG. 4A) to theextended position (see, e.g., FIG. 4B) in preparation for administrationof the intradermal injection. Administration will typically involvepressing the skin engaging surface 10 of the limiter 32 substantiallyperpendicular to a surface of the patient's skin. The health careprofessional will maintain this orientation so as to maintain the needlein a position substantially perpendicular with the skin surface. Thedrug substance will then be injected using the plunger or other deviceconventionally used to deliver a drug substance. The injection willcontinue for a period of time determined by one having skill in the artbased on the particular substance being administered as well as thedosage volume. Upon completion of the injection, the health careprofessional withdraws the needle cannula 4 from the patient's skin anddisposed of the used injection device 1 in a suitable container.

Although the subject invention is well-suited for filling atpoint-of-use, it can be pre-filled. Optionally, for a prefilled device,a protective cap (not shown) may be provided for covering the needlebefore use, with the cap being positioned over the needle tip 6 and skinengaging surface 10. Preferably, the cap is formed from an elastomericmaterial or thermoplastic elastomer that allows for the forward tip 6 topenetrate the cap and thus be sealed thereby 34. Accordingly, the cap,by sealing the needle cannula 4, seals the reservoir and prevents thesubstance therein from leaking into the needle cannula 4 prior toadministration of the intradermal injection. Such a cap also provides acertain degree of sterility for the needle tip 6 and maintains itssharpness.

Additionally, a shield member may also be provided for covering theneedle tip 6 after use of the inventive injection device 1. Such ashield may be provided as part of the outer sheath 34, or as a componentseparate therefrom. Alternatively, the shield may be provided by thesheath 34 and support member 36, such as, for example, by providingadditional complementary and interacting features on each part. Suchfeatures permitting further movement of the sheath 34 from the extendedposition to a shielding position in which the needle tip 6 is completelyenclosed within the sheath 34, and the sheath 34 is lockingly secured tothe support member 36 in the shielding position. in another alternativeembodiment, a needle shield may be hingedly attached to a part of theneedle assembly 2 or syringe 14. Other equivalent structures may also beused for this purpose.

While the invention has been described in relation to the preferredembodiments with several examples, it will be understood by thoseskilled in the art that various changes may be made without deviatingfrom the spirit and scope of the invention as defined in the appendedclaims.

1. A drug delivery device for use in administering injections byproviding access to a medication vial, said medication vial having apiercable closure septum, said septum having a septum thicknessdimension, wherein the vial comprises a sealed chamber filled with aninjectable substance; the device comprising: a needle cannula having alumen and a needle tip; a limiter surrounding said needle cannula andhaving an engaging surface, wherein said limiter is moveable from afirst position in which an elongate portion of said needle cannula isexposed a first penetration distance from about 5 mm to about 15 mm fromsaid engaging surface, thereby allowing the needle lumen to access tothe chamber of said vial, to a second position in which said limiter isnot movable from said second position to said first position and inwhich said needle tip extends beyond said engaging surface apre-selected second penetration distance, wherein said secondpenetration distance is less than said septum thickness dimension; and acontainer adapted to contain said substance for injection, saidcontainer being in fluid communication with said needle cannula.
 2. Thedrug delivery device of claim 1, wherein said second penetrationdistance is a skin penetration distance and is about 0.5 mm to about 3mm.
 3. The drug delivery device of claim 1, wherein said secondpenetration distance is a skin penetration distance and is about 0.5 mmto about 2 mm.
 4. The drug delivery device of claim 3, wherein saidneedle tip extends beyond said engaging surface a distance of about 1 toabout 2 mm.
 5. The drug delivery device of claim 1, wherein saidengaging surface is substantially planar.
 6. The drug delivery device ofclaim 1, wherein said limiter comprises: a support member about saidneedle cannula; and an outer sheath arranged about said support memberand selectively slidable with respect thereto from said first positionto said second position.
 7. The drug delivery device of claim 6, whereinsaid limiter further comprises a first means for releasably holding saidouter sheath in said first position, and a second means for lockinglyholding said sheath in said second position.
 8. The drug delivery deviceof claim 7, wherein said first means comprises a retaining projectionand stop member on said support member and a projection on said sheath.9. The drug delivery device of claim 8, further comprising a recessproximal said retaining projection for accommodating said inwardlydirected projection of said sheath when said limiter is in said firstposition.
 10. The drug delivery device of claim 6, wherein said supportmember includes a distal stop toward a distal end of said supportmember, a ramp proximal to said outwardly directed projection and anindent interposed therebetween, wherein said inwardly directedprojection resides within said indent when said limiter is in saidsecond position.
 11. The drug delivery device of claim 10, wherein saidinwardly directed projection includes a proximal edge, said rampincludes a distal edge, whereby said proximal edge is in abuttingcontact with said distal edge when said limiter is in said secondposition.
 12. The drug delivery device of claim 6, further comprising ahub about said needle cannula, said hub being adapted to accept acontainer for delivering a substance.
 13. The device of claim 12,wherein said hub and said support member are unitarily formed.